1. Field
The present disclosure generally relates to optical communication and, more particularly, to optical cable assemblies, optical engines and methods for transitioning an optical communications link into and out of a sleep mode.
2. Technical Background
As the data rate of communication protocols increases, it becomes difficult to transmit signals using purely electrical cables. Optical communication has provided a solution to the distance versus data rate problem for the telecommunication and data center markets. Benefits of optical fiber include longer reach, extremely wide bandwidth and low noise operation. Because of these advantages, optical fiber is increasingly being used for a variety of applications, including, but not limited to, broadband voice, video, and data transmission. Optical fiber is emerging as the lowest cost and most compact interconnect technology in an increasing number of consumer electronics applications, especially at lengths greater than a few meters.
Some data transmission interfaces require low-speed data (e.g., control data at data rates such as 1 Mb/s) to be transmitted simultaneously with high-speed data (e.g., 10 Gb/s and beyond). However, the additional low-speed data require an additional transmission medium, such as copper conductors or additional optical fibers. The additional transmission medium may increase the diameter of the optical cable, and, in the case of copper conductors, require DC isolation between ends of the optical cable as well as provide additional shielding requirements due to electro-magnetic interference concerns.
The ability to detect physical or logical disconnect events of an optical cable assembly while in a low power state is a challenge because it requires some form of communication between the ends of the optical cable assembly. In a traditional copper cable assembly, the process of detecting a disconnect event is relatively simple because all that is needed is to determine whether or not one or more of the copper wires spanning the length of the cable assembly is connected at both ends.